1. FIELD OF THE INVENTION
The present invention relates to vicaminic acid derivatives, and more particularly relates to vincaminic acid derivatives having the therapeutic effect on cerebovascular injuries.
2. DESCRIPTION OF THE PRIOR ART
There are already known some vincaminic acid derivatives having cerebral vasodilating effect, protective effect on cerebral ischemia, cerebral metabolic accelerating effect and the like (British Pat. Nos. 2,062,619A and l,492,579A and European Pat. No. 170,926A).
However, the pharmacological effect of the prior art compounds is not sufficient, and there is a need for appearance of the vincaminic acid derivatives having improved cerebral vasodilating effect, protective effect on ischemia, and cerebral methabolic accelerating effect.